There has hitherto been known a swash plate compressor which is provided with a swash plate which rotates around a rotary shaft, a piston which moves forward and backward in response to the rotation of the swash plate and in which a hemispherical concave sliding surface is formed, and a shoe in which there are formed a flat end surface portion which comes into sliding contact with the above-described swash plate and a spherical surface portion which comes into sliding contact with the above-described sliding surface formed in the above-described piston (Patent Literature 1 and Patent Literature 2).
In the swash plate compressor of Patent Literature 1, in order to ensure the lubrication of a sliding surface of the above-described piston and a spherical surface portion of the shoe, the surface roughness of a non-sliding portion in the spherical surface portion of the shoe which does not come into sliding contact with the above-described sliding surface is made large, whereby a lubricating oil is held in the non-sliding contact part.
In the swash plate compressor of Patent Literature 2, the weight of a shoe is reduced by making the shoe hollow and the inertial force to the shoe caused by the reciprocating motion of a piston is reduced, whereby the sliding performance between the sliding surface of the piston and the spherical surface portion of the shoe is improved.